Observation: Turnagain

Location: Tincan

Date:
Observer:
Route & General Observations

Standard route to 3200′.
No rain on snow at 1000′ at Turnagain. Rain/snow line was around 800′. Of note Girdwood observers reported it at 1000′ and a Summit observer a bit higher.

Height of snow near the Tincan avalanche warning sign @ 1000′: 190 cm/6.2′.

Red Flags
Red flags are simple visual clues that are a sign of potential avalanche danger. Please record any sign of red flags below.
Obvious signs of instability
Recent Avalanches?Yes
Collapsing (Whumphing)?Yes
Cracking (Shooting cracks)?No
Observer Comments

We saw recent avalanches along the Seward Highway from Girdwood south including on Orca on the north end and on Begich Peak near the Portage turn. A few of the paths off of Seattle Ridge, south of the uptrack had new debris but crowns were blown in. We saw recent avalanches just north of Pastoral but could only make out debris piles from a distance. We spotted a crown on the south side of Wolverine and two on the southwest side of 4710'.

As we were getting back towards the truck we each experienced a couple very noticeable whumpfs, some while on the well traveled skin track.
No cracking or whumpfs while skinning up or skiing down.

Weather & Snow Characteristics
Please provide details to help us determine the weather and snowpack during the time this observation took place.
Weather

Scattered clouds becoming partly cloudy to mostly cloudy in the afternoon.
Light flurries while loading up the truck at 3:15 pm
Temperatures in the 20°Fs
Light east/southeast winds

Snow surface

Soft snow, ski pen was around 8-10" from 1000' up to 2000'. Once we got into more wind exposed terrain it was 6" or less.
Height of new snow was 3'.

Snowpack

From 1000' to 2000' below the soft 8-10" there was dense moist snow.
Once we hit terrain more exposed to the wind the soft snow was on dense wind compacted snow.
In wind affected areas the height of the new snow was quite variable.

Pit at 1800': HS: 240 new snow was 100 cm, December 1st crust facet sandwich was down 115 cm. Compression tests - CT 18, CT 12 just below the thin upper crust.

Two pits at 2200' (see photos) - HS 175, HS 215. South aspect. 22° slope. The new snow/old snow interface was easy to pick out with a thin layer of buried stellars, it was down 30cm and 40 cm in the two adjacent pits. We had extended column test results on this layer ECTP 11, 12, 13 and 15. In addition we found the December 1st crust facet sandwich down 65 cm and 85 cm in the 2 pits. ECTs were failing under the thin upper crust on small facets. ECTP 21, ECTP 29, ECTN24. In another pit across the way on a north aspect in a more wind loaded spot the new snow was 75cm deep and tests were less reactive on both layers.

Pit at 3200' - HS: 190cm, southwest aspect, 27°, new/old interface with buried stellars down 55 cm ECTP 18. There is not a buried crust at this elevation. In another nearby pit this layer was 100 cm down with an ECTP26 and in pit number 3 ECTX.

Photos & Video
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